The invention relates to an oil collecting unit for collecting oil from the water surface, comprising a rotating oil-collecting brush element, a motor rotating the brush element, and a comb member removing oil from the brush element, the brush element being arranged to press the oil below the water surface and then lift it up through the bottom dead center, so that the water adhering to the brushes drops off, and the oil is removed from the brushes by means of the comb member. In particular, the invention is concerned with an oil collecting apparatus which is suited for temporary or rapid installations and which forms an independent entity.
SE Patent Specification 346346, U.S. Patent Specification 3,617,555, and FI Patent Specification 70443 disclose oil collecting apparatuses provided with cylindrical or broad weblike brush elements. A problem with such collecting apparatuses is that oil-containing water tends to escape from the front of the collecting element to the sides so that the brush fibers of the collecting element do not appropriately catch the oil to be collected. GB Patent Specification 2063696 discloses an oil collecting apparatus provided with several disc plates to the surface of which oil sticks and can be removed therefrom. Despite the great number of plates, the capacity of such apparatuses has proved to be low. FI Patent Specification 71596 discloses an oil collecting apparatus in which a mat provided with brush fibers is placed obliquely around rolls, the mat being formed by several parallel chains to which the brush fibers are attached. Water is able to flow through the chains, which prevents the escape of oil-containing water from the front of the apparatus, which, as mentioned above, is a frequent problem with cylindrical brush elements. This kind of apparatus is of necessity rather large in size.